U.S. patent number 5,491,646 [Application Number 07/982,672] was granted by the patent office on 1996-02-13 for production of anaglyphs.
Invention is credited to Stephen P. E. Erskine.
United States Patent |
5,491,646 |
Erskine |
February 13, 1996 |
Production of anaglyphs
Abstract
A method for producing and anaglyph includes the steps of:
producing a first image color record having at least two color
numbers per pixel and representing the distribution of at least
first and second image colors in one of the images of a stereo pair
of images; producing a second image color record having at least
one color number per pixel and representing the distribution of a
least a third image color in the other of the stereo pair of
images; combining the first image color record with the second
image color record to produce an anaglyph color record having at
least three color numbers per pixel, the three color numbers of the
anaglyph color record corresponding to first, second and third
anaglyph colors, and anaglyph color record representing the
distribution of the anaglyph colors in the anaglyph.
Inventors: |
Erskine; Stephen P. E.
(Uffington, Oxfordshire, SN7 7RB, GB2) |
Family
ID: |
10704909 |
Appl.
No.: |
07/982,672 |
Filed: |
November 20, 1992 |
Foreign Application Priority Data
|
|
|
|
|
Nov 20, 1991 [GB] |
|
|
9124613 |
|
Current U.S.
Class: |
382/154;
348/E13.033; 348/E13.037; 356/12; 382/162; 382/285; 345/419 |
Current CPC
Class: |
H04N
13/334 (20180501); H04N 13/324 (20180501) |
Current International
Class: |
G09C
5/00 (20060101); H04N 13/00 (20060101); G02B
027/02 () |
Field of
Search: |
;364/514,526
;359/464,478,462,466 ;354/112 ;395/119 ;356/12 ;353/7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Voeltz; Emanuel T.
Assistant Examiner: Peeso; Thomas
Attorney, Agent or Firm: Young & Thompson
Claims
What I claim is:
1. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each digital image colour record including a series of colour
numbers representing the colours respectively of an array of
visible individual coloured pixels into which the respective image
is divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least one colour
number for each pixel of the second image, said one colour number
representing the proportion of a third image colour in the colour
of the respective pixel;
combining said first digital image colour record with said second
digital image colour record, to produce a single anaglyph digital
colour record, by mathematically processing the colour numbers of
the first and second image records respectively in a manner to
derive a third series of colour numbers, said third series of
colour numbers constituting said single anaglyph digital colour
record and representing the colours respectively of an array of
visible individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel.
2. A method of producing an anaglyph as claimed in claim 1, which
further includes the step of displaying the anaglyph corresponding
to the anaglyph colour record.
3. A method as claimed in claim 1, wherein the three anaglyph
colours are chosen so that no one of the three anaglyph colours can
be formed by any combination of the other two anaglyph colours.
4. A method as claimed in claim 1, wherein the three image colours
are chosen so that no one of the three image colours can be formed
by any combination of the other two image colours.
5. A method as claimed in claim 1, wherein the three image colours
are chosen to be the same as the three anaglyph colours.
6. A method as claimed in claim 1, wherein the first and second
image colour records each have at least three colour numbers per
pixel, the three colour numbers corresponding respectively to the
three image colours.
7. A method as claimed in claim 1, which further includes the step
of adjusting the values of the colour numbers corresponding to at
least one of the image colours in at least one of the image colour
records.
8. A method as claimed in claim 7, wherein the step of adjusting
the colour numbers is carried out before the two image colour
records are combined.
9. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each said digital digital colour record including a series of
colour numbers representing the colours respectively of an array of
visible individual coloured pixels into which the respective image
is divided;
said first digital image colour record having three colour numbers
for each pixel of the first image, said three colour numbers
representing the proportions respectively of first, second and
third image colours in the colour of the respective pixel;
said second digital image colour record having at least one colour
number for each pixel of the second image, said one colour number
representing the proportion of said third image colour in the
colour of the respective pixel;
adjusting the colour numbers of the first image colour record so
that said third image colour is entirely, or almost entirely,
removed from said first image of the stereo pair of images;
combining said first image colour record with said second image
colour record, to produce a single anaglyph digital colour record,
by mathematically processing the colour numbers of the first and
second image records respectively in a manner to derive a third
series of colour numbers, said third series of colour numbers
constituting said single anaglyph digital colour record and
representing the colours respectively of an array of visible
individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel.
10. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each digital colour record including a series of colour numbers
representing the colours respectively of an array of visible
individual coloured pixels into which the respective image is
divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least two colour
numbers for each pixel of the second image, said two colour numbers
representing the proportions respectively of said first colour and
a third image colour in the colour of the respective pixel;
adjusting the numbers of the second image colour record so that
said first digital image colour is entirely, or almost entirely
removed from said second digital image of the stereo pair of
images;
combining said first digital image colour record with said second
digital image colour record, to produce a single anaglyph digital
colour record, by mathematically processing the colour numbers of
the first and second image records respectively in a manner to
derive a third series of colour numbers, said third series of
colour numbers constituting said single anaglyph digital colour
record and representing the colours respectively of an array of
visible individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel.
11. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each digital colour record including a series of colour numbers
representing the colours respectively of an array of visible
individual coloured pixels into which the respective image is
divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least one colour
number for each pixel of the second image, said one colour number
representing the proportion of a third image colour in the colour
of the respective pixel;
adjusting the colour number in the first image colour record
corresponding to the second image colour so that the amount of the
second image colour present in said first image of the stereo pair
of images is reduced by between 10% and 40%, or between 20% and
30%, relative to the amount of said first image colour in said
first image of the stereo pair of images;
combining said first image colour record with said second image
colour record, to produce a single anaglyph digital colour record,
by mathematically processing the colour numbers of the first and
second image records respectively in a manner to derive a third
series of colour numbers, said third series of colour numbers
constituting said single anaglyph digital colour record and
representing the colours respectively of an array of visible
individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel.
12. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each digital colour record including a series of colour numbers
representing the colours respectively of an array of visible
individual coloured pixels into which the respective image is
divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least two colour
number for each pixel of the second image, said two colour numbers
representing the proportions respectively of said second digital
image colour and a third image colour in the colour of the
respective pixel;
adjusting the numbers of the second image colour record so that
said second image colour is entirely, or almost entirely, removed
from said second image of the stereo pair of images;
combining said first digital image colour record with said second
digital image colour record, to produce a single anaglyph digital
colour record, by mathematically processing the colour numbers of
the first and second image records respectively in a manner to
derive a third series of colour numbers, said third series of
colour numbers constituting said single anaglyph digital colour
record and representing the colours respectively of an array of
visible individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel.
13. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
each digital colour record including a series of colour numbers
representing the colours respectively of an array of visible
individual coloured pixels into which the respective image is
divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least one colour
number for each pixel of the second image, said one colour number
representing the proportion of a third image colour in the colour
of the respective pixel;
combining said first digital image colour record with said second
digital image colour record, to produce a single anaglyph digital
colour record, by mathematically processing the colour numbers of
the first and second image records respectively in a manner to
derive a third series of colour numbers, said third series of
colour numbers constituting said single anaglyph digital colour
record and representing the colours respectively of an array of
visible individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective
pixel;
said mathematical processing including calculating the average
amount of each image colour present in corresponding pixels of the
two images of said stereo pair of images, and assigning values to
the colour numbers of the anaglyph colour record in such a way as
to ensure that each pixel of the anaglyph contains an amount of
each image colour equal, or substantially equal, to the average
amount of that image colour present in the corresponding pixels of
said two images.
14. A method for producing an anaglyph, the method including the
steps of:
producing a first digital image colour record representing a first
image of a stereo pair of images;
producing a second digital image colour record representing a
second image of said stereo pair of images;
said first digital image color record and said second colour image
color record being produced by digitising images of an object,
which images have been formed by any kind of electromagnetic
radiation reflected from, or emitted by, the object;
each digital colour record including a series of colour numbers
representing the colours respectively of an array of visible
individual coloured pixels into which the respective image is
divided;
said first digital image colour record having at least two colour
numbers for each pixel of the first image, said two colour numbers
representing the proportions respectively of first and second image
colours in the colour of the respective pixel;
said second digital image colour record having at least one colour
number for each pixel of the second image, said one colour number
representing the proportion of a third image colour in the colour
of the respective pixel;
combining said first digital image colour record with said second
digital image colour record, to produce a single anaglyph digital
colour record, by mathematically processing the colour numbers of
the first and second image records respectively in a manner to
derive a third series of colour numbers, said third series of
colour numbers constituting said single anaglyph digital colour
record and representing the colours respectively of an array of
visible individual coloured pixels defining an anaglyph;
said single anaglyph digital colour record having at least three
colour numbers for each pixel of the anaglyph, said three colour
numbers representing the proportions respectively of first, second
and third anaglyph colours in the colour of the respective pixel.
Description
The invention relates to a method for producing anaglyphs.
In this specification, an anaglyph is defined as any two
dimensional image which, when viewed through anaglyph spectacles,
gives the appearance of being a three dimensional image.
Anaglyph spectacles ar defined as any device which ensures that
each eye of a person viewing the anaglyph receives from the
anaglyph a different frequency distribution of light.
Anaglyphs are conventionally formed from two photographs, or two
motion films, which have been taken from slightly different
positions, usually spaced laterally apart by a distance
corresponding to the separation between a person's eyes, so as to
produce two slightly different images, commonly referred to as a
stereo pair of images, One of the images is usually coloured red
and the other blue or green so that, when the two images are viewed
through spectacles having one red lens and one blue lens, one eye
sees one image and the other eye sees the other image, thus giving
the appearance of depth. The two images are normally
superposed.
Computer-generated anaglyphs have also been formed by combining
image data for two differently coloured monochrome images. An image
may be stored by a computer in the form of a colour record. In this
specification a colour record is defined as a sequence of numbers
representing the colour distribution of an image. The image is
divided into pixels, and the colour record contains a series of
numbers, or groups of numbers, each number, or group of numbers,
representing the colour of an individual pixel. A number of
different formats are commonly used for such colour records, and
the particular format employed depends to a large extent upon the
amount of information which can be stored by the computer. Thus,
computer using 8 bits per pixel can use a maximum of 256 colours in
any one image, whereas a computer using 24 bits per pixel can use
up to 16,77,214 different colours.
In some formats the colour record contains three separate numbers
for each pixel of the image, the three numbers representing the
respective amounts of three different colours present in the pixel.
For example, in the "Truevision Targa-24" format the colour record
had eight bits representing the amount of red in the first pixel,
followed directly by eight bits representing the amount of green in
the first pixel, then eight bits for the amount of blue in the
first pixel, followed by 8 bits for the red in the second pixel,
and so on for every pixel of the image. In this specification, such
numbers are referred to as colour numbers. That is, a colour number
represents the amount of a particular colour, usually one of three,
in a particular pixel. The colour numbers need not represent the
colours red, green and blue respectively, although red, green and
blue have been found to be capable of producing an enormous range
of colours, when combined in different proportions, and are
therefore the most popular choice. Whichever format is used, it is
always possible to transform the colour record to a different
format, although if the new format uses fewer bits per pixel then
some loss of colour range will usually occur.
Anaglyphs produced by computer have been formed by combining image
data for two differently coloured monochrome images so as to form a
single image, i.e. an anaglyph, which can be displayed on a
VDU.
However, anaglyphs formed as described above, using either
photography or a computer, where each original image is monochrome,
have not been found to produce a particularly broad or realistic
range of colours when viewed through anaglyph spectacles.
SUMMARY OF THE INVENTION
According to the invention there is provided a method for producing
an anaglyph, the method including the steps of: producing a first
image colour record having at least two colour numbers per pixel
and representing the distribution of at least first and second
image colours in one of the images of a stereo pair of images;
producing a second image colour record having at least one colour
number per pixel and representing the distribution of at least a
third image colour in the other of the stereo pair of images;
combining the first image colour record with the second image
colour record to produce an anaglyph colour record having at least
three colour numbers per pixel, the three colour numbers of the
anaglyph colour record corresponding to first, second and third
anaglyph colours, and the anaglyph colour record representing the
distribution of said anaglyph colours in the anaglyph.
The method may also include the step of displaying the anaglyph
corresponding to the anaglyph colour record.
It will be appreciated that the visual image resulting from viewing
such an anaglyph through anaglyph spectacles may comprise colours
produced by any combination of the three anaglyph colours.
Therefore, such an image may be more colourful and/or realistic
than images derived from conventionally produced anaglyphs.
It will also be appreciated that the stereo pair of images need not
correspond to any real physical object, and could, for example, be
generated by a computer and, of course, the method according to the
invention is particularly suitable for performance by a
computer.
Preferably, the three anaglyph colours are chosen so that no one of
the three anaglyph colours can be formed by any combination of the
other two anaglyph colours.
It is also preferable that the three image colours are chosen so
that no one of the three image colours can be formed by any
combination of the other two image colours.
Conveniently, the three image colours are chosen to be the same as
the three anaglyph colours.
In one embodiment of the invention, the first and second image
colour records each have at least three colour numbers per pixel,
the three colour numbers corresponding respectively to the three
image colours.
The method may also include the step of adjusting the values of the
colour numbers corresponding to at least one of the image colours
in at least one of the image colour records, preferably before the
two image colour records are combined.
For example, if the first image colour record contains colour
numbers corresponding to the third image colour, then these colour
numbers may be adjusted so that the third image colour is entirely,
or almost entirely, removed from said one of said stereo pair of
images.
Additionally or alternatively, if the second image colour record
contains colour numbers corresponding to the first image colour
then these colour numbers may be adjusted so that the first image
colour is entirely, or almost entirely, removed from said other of
said stereo pair of images.
Each colour number in the first image colour record corresponding
to the second image colour may be adjusted so that the amount of
the second image colour present in said one of said stereo pair of
images is reduced by between 10% and 40%, or by between 20% and
30%, relative to the amount of the first image colour in said one
of said stereo pair of images.
If the second image colour record contains numbers corresponding to
the second image colour, then these colour numbers may be adjusted
so as to entirely, or almost entirely, remove the second image
colour from said other of said stereo pair of images.
Preferably, the step of combining the first and second image colour
records includes calculating the average amount of each image
colour present in corresponding pixels of the two images of said
stereo pair of images, and assigning values to the colour numbers
of the anaglyph colour record in such a way as to ensure that each
pixel of the anaglyph contains an amount of each image colour
equal, or substantially equal, to the average amount of the image
colour present in the corresponding pixels of said two images.
The steps of producing the first and second image colour records
may include digitising images of an object, which images have been
formed by any kind of electromagnetic radiation reflected from, or
emitted by, the object.
The invention also provides apparatus for performing any of the
methods described above, the apparatus comprising digitising means
for digitising information relating to the distribution of colours
in a stereo pair of images, processing means for adjusting the
colour numbers of the first and second image colour records, and
for combining the first and second image colour records so as to
produce the anaglyph colour record, and display means for
displaying the anaglyph corresponding to the anaglyph colour
record.
The processing means may be a dedicated micro-processor, or a
computer, or personal computer, set up to run a suitable
program.
The invention also provides, in a second aspect thereof, a method
of encoding information by means of a stereo pair of images,
wherein each image comprises an array of shapes, for example dots,
the shapes being so arranged that, when the stereo pair of images
is viewed through a stereoscope, some of the shapes appear to be
closer to the viewer then the other shapes, the information being
in alphanumeric form and being contained in the arrangement of the
shapes which appear to be closer to the viewer, or of those shapes
which appear to be further away from the viewer, and such
information not being perceivable by viewing either image
alone.
A stereoscope is any device which enables one eye of the viewer to
see only one image, and the other eye of the viewer to see only the
other image, of a stereo pair of images.
It will be appreciated that the encoded information stored by means
of such a stereo pair of images could be revealed by means of a
computer, without the need for a person to actually view the stereo
pair of images, if the computer were to be provided with
information relating to the two arrays.
The invention also provides a stereo pair of images when produced
by the above method.
In one embodiment of the invention, the shapes of at least one of
the images are arranged as a random array.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One example of the invention will now be described.
A stereo pair of images corresponding to two full colour
photographs is stored in digital form by a computer in two image
files. This can be done by using a so called "flat bed colour
scanner" in known manner. The photographs are simply placed on the
flat bed scanner, which then converts the information stored in the
photographs into digital form. The two image files are stored in
"Truevison Targa-24" format which uses 24 bits per pixel, 8 bits
for red, 8 bits for green, and 8 bits for blue.
Before the two image files are combined to produce an anaglyph, all
of the colour numbers corresponding to green and blue in the second
image file are set to zero, the colour numbers corresponding to red
in the first image file are also set to zero, and the colour
numbers corresponding to green in the first image file are reduced
by 25%, i.e. by multiplying each colour number corresponding to
green in the first image file by 0.75.
The two image files are then combined using a program called
"Average" which is part of a software package called "ImageTools"
written by John Bridges. This software enables the two image files
to be averaged to produce a single image file. That is, the single
image file is generated by averaging the value of each colour
number of each pixel in the first of the two image files with the
value of the same colour number of the corresponding pixel in the
second of the two image files. The resulting single file then
corresponds to an anaglyph, in accordance with the present
invention.
The resulting anaglyph therefore contains a large range of colours
formed from different combinations of red, green and blue. The
anaglyph may be displayed on VDU, or colour printer, and viewed
through a pair of anaglyph spectacles having one red filter and one
cyan blue filter, to give an appearance of depth.
It is not fully understood how the human brain combines the two
images to produce the visual sensation of a multi-coloured image.
It might be thought at first sight that, because the lenses are red
and blue, only colours formed by combining the two colours red and
blue will be observed. However, it has been found that a very large
range of colours can be observed when the anaglyph is viewed
through such anaglyph spectacles, and that the appearance of the
anaglyph is very close to that of the original photographs, as
regards colour. This may be due to the fact that the red and blue
lenses let through a range of different colours in addition to red
and blue.
It will be appreciated that in the above method, since the colour
numbers corresponding to green and blue in the second image file
are set to zero, the same effect may be achieved by omitting such
colour members from the second image file ab initio. The second
image file will then contain only information relating to the red
colour content of one of the images, and similarly the second image
file may only contain information relating to the green and blue
colour content of the other image. It follows, therefore, that
image files suitable for generating an anaglyph could be formed by
scanning one of the two photographs with the flat bed scanner set
to receive and/or transmit one combination of colours, in this case
only red, and by scanning the other of the two photographs with the
flat bed scanner set to receive and/or transmit a different
combination of colours, in this case blue and 75% green.
Furthermore, it is possible to conceive of applications of the
invention which allow an object which has been designed by, or with
the aid of, a computer to be coloured by an operator. The computer
could then create a stereo pair of image files, one containing only
red colour numbers, and the other containing only green and blue
colour numbers, which could then could be combined to form the
image file of an anaglyph which would appear in full colour when
viewed through anaglyph spectacles having a red and a blue
filter.
It will also be appreciated that, because it is possible to use
different combinations of different colours to form the same
colour, the three colours used in the image file for the anaglyph
need not necessarily be the same as the three colours which are
used in the two image files for the initial stereo pair of images,
although it will usually be convenient to use the same three
colours for all of the image files.
Anaglyphs produced by the above method may be displayed on
computers with colour display systems, or output via appropriate
software and hardware to devices such as colour television screens,
colour video printers, and a variety of colour hard copy devices;
or they may be transferred, for example by modem, to sites where
such equipment is available. Anaglyphs corresponding to stereo
pairs of images taken from a wide variety of sources may be created
by this method. Such sources include photographs, slides,
photogrammetric images, medical images, and images created "de
novo" using a computer. A monochrome stereo pair of images may be
pseudo-coloured before being converted into anaglyphs in order to
facilitate and enhance the interpretation or analysis of the
anaglyph. Furthermore, a sequence of anaglyphs may be created to
give the appearance of a moving subject. The invention has
potential applications in the fields of, for example,
photogrammetry (including mapping, satellite image analysis, and
oil exploration), medicine, natural science, computer aided design,
architecture, archaeology, meteorology, entertainment and defence.
Furthermore, all that is required in order to perform the method is
a personal computer with a suitable colour display system and a
pair of anaglyph spectacles.
* * * * *